Dental floss is defined in Webster's New World Dictionary, 1983, as “ . . . thread for removing food particles between the teeth.”
The concept of using dental floss for cleansing interproximal spaces appears to have been introduced by Parmly in 1819, Practical Guide to the Management of Teeth, Cullins & Croft Philadelphia, Pa. Numerous types of floss were developed and used for cleaning interproximal and subgingival surfaces, until finally in 1948 Bass established the optimum characteristics of dental floss, Dental Items of Interest, 70, 921–34 (1948).
Bass cautioned that dental floss treated with sizing, binders and/or wax produces a “cord” effect as distinguished from the desired “spread filament effect”. This cord effect reduces flossing efficiency dramatically and visually eliminates splaying (i.e., the flattening and spreading out of filaments) necessary to achieve the required interproximal and subgingival mechanical cleaning. This cleaning is then required to be followed by the entrapment and removal of debris, plaque and microscopic materials from interproximal spaces by the “spread” floss as it is removed from between teeth.
Proper use of dental floss is necessary to clean the considerable surface area on the interproximal surfaces of teeth, which cannot usually be reached by other cleaning methods or agents, e.g., the bristles of a toothbrush, the swishing action of a rinse, or by the pulsating stream from an oral irrigator.
Historically, the purpose of dental floss was to:
                (1) dislodge and remove any decomposing food material, debris, etc., that has accumulated at the interproximal surfaces, which could not be removed by other oral hygiene means, and        (2) dislodge and remove as much as possible the growth of bacterial material (plaque, tartar, calculus) that had accumulated there since the previous cleaning.        
Effective oral hygiene requires that three control elements be maintained by the individual:                (1) Physical removal of stains, plaque and tartar. This is accomplished in the strongest sense by scraping and abrasion in the dentist's office. Self administered procedures are required frequently between visits and range from tooth brushing with an appropriate abrasive toothpaste through flossing and water jet action down to certain abrasive foods and even the action of the tongue against tooth surfaces.        (2) Surfactant Cleaning. This is required to remove: food debris and staining substances before they adhere to the tooth surface; normal dead cellular (epithelial) material which is continually sloughed off from the surfaces of the oral cavity and microbial degradation products derived from all of the above. Besides the obvious hygienic and health benefits related to simple cleanliness provided by surfactants, there is an important cosmetic and sense-of-well-being benefit provided by surfactant cleansing. Research has shown that the primary source of bad breath is the retention and subsequent degradation of dead cellular material sloughed off continuously by the normal, healthy mouth.        (3) Frequency of Cleansing. This is perhaps the most difficult to provide in today's fast-paced work and social environment. Most people recognize that their teeth should be brushed at least 3 times a day and flossed at least once a day. The simple fact is that most of the population brush once a day, some brush morning and evening, but precious few carry toothbrush and dentifrice to use the other three or four times a day for optimal oral hygiene. Consumer research suggests that the population brushes an average of 1.3 times a day. Most surprising, less than 15% of adults floss regularly. Reasons offered for not flossing: difficult to do, painful, not effective, doesn't seem to do anything, and leaves a bad taste.        
It is generally accepted that multifilament dental floss is not a “user-friendly” product, i.e., it is difficult to do. It caused pain and bleeding and it results in a bad taste in the mouth. Most market researchers agree that anything that can be done to make flossing more positive should be implemented to encourage more frequent flossing and more wide spread floss use. The addition to floss of: full spectrum flavor oils, mouth conditioning substances such as silicones along with cleaners and abrasives that are perceived as “working” as taught by the present invention, are all sources of positive feed back to the flosser that would be considered encouraging and supportive. To achieve these requires basic changes in present floss manufacturing.
Three basic nylon fiber bundle constructions have been previously approved by the Food and Drug Administration (FDA) which has classified multifilament dental floss as a medical device. The three basic constructions are: 140 denier (68 filament) 100 denier (34 filament) and 70 denier (34 filament). Heretofore, 6 to 10 bundles of these three types were twisted together along with bonding agents to produce various commercial multifilament dental flosses.
Most commercial multifilament interproximal devices marketed at the present time contain various coatings of wax or wax like substances that function as: (1) binders for the various multifilament flosses to minimize fraying, (2) lubricants, (3) flavor carriers, and/or (4) fluoride carriers.
An almost universal shortcoming common to most waxed multifilament dental flosses is the user perception during flossing that the dental floss is “not working” and/or “not cleaning”, etc.
In fact, most of these devices have only marginal efficacy with respect to removing biofilms (plaque). Biofilms generally require physical abrasive-type action to be effectively removed. Periodic professional cleaning is a recommended means for effectively controlling biofilm formation.
From 1960 thru 1982, numerous clinical studies reported that there is no clinical difference as to plaque removal and gingivitis scores between waxed and unwaxed multifilament dental floss. Note, both are “cord” flosses and contain sizing, binders, etc. These studies also confirmed that waxed and unwaxed floss are approximately 50% effective with respect to plaque removal and gingivitis scores. Thus the “cord” effect severely restricts efficiency of flossing and especially physical abrasive-type action associated with multifilament flosses that splay as described by Bass.
O'Leary in 1970, and Hill et al. in 1973, found no difference in the interproximal cleansing properties of waxed and unwaxed dental floss. This was reconfirmed in 1982 by Lobene et al. who showed no significant clinical difference on plaque and gingivitis scores. Similar results, i.e., no clinical difference between waxed and unwaxed multifilament dental floss with respect to reduced gingival inflammation were shown by Wunderlich in 1981. No differences in plaque removal were reported by Schmidt et al. in 1981 with multifilament flosses of various types. Stevens, 1980, studied multifilament dental floss with variable diameters and showed no difference in plaque and gingival health. Carter et al. 1975, studied professional and self administered waxed and unwaxed multifilament dental floss, both significantly, reduced gingival bleeding of interproximal and gingival sulci. Unwaxed multifilament dental floss appeared slightly, but not significantly more effective.
In view of this clinical work, it is not surprising that most of the multifilament dental floss sold today is contrary to the teaching of Bass, bonded and/or waxed. The “bonding” in the yarn industry today is used more to facilitate processing and production during multifilament dental floss manufacture and packaging than for “flossing” reasons. Since clinical tests show no difference between waxed and unwaxed multifilament dental floss (both unfortunately are “bonded”), the multifilament dental floss industry has been comfortable with the yarn industry's propensity to use bonding agents in multifilament dental floss, thereby sacrificing splaying and physical abrasive-type cleaning.
As noted above, there are three basic nylon strand constructions approved by the FDA for multifilament dental floss. These are 140 denier (68 filament), 100 denier (34 filament) and 70 (34 filament). Analysis of the commercial multifilament dental flosses sold worldwide show that almost all multifilament dental flosses available are twisted in generally the same manner, contain bonding agents, and are constructed by twisting several (6–10) strands selected from one of these three strand types.
The commercialization of the innovative multifilament dental flosses described and claimed in U.S. Pat. Nos. 4,911,927; 5,098,771; 5,165,913 and 5,711,935 to Hill et al. has extended the purpose of multifilament dental floss to include the release therefrom of chemotherapeutic agents, both interproximally and subgingivally. The efficacy of these new multifilament dental flosses has been documented in clinical studies reported in a filing responsive to the FDA call-for-data of Sep. 19, 1990, 55 Fed. Reg. 38560. See Docket No. 81N-0033, OTC 210246 to 210262. The Hill et al. patents and the referenced clinical studies are hereby incorporated herein by reference.
The Hill et al. patents teach that satisfactory multifilament dental flosses can be manufactured having loadings up to 100% of the substrate weight. These patents to Hill et al. taught that the floss loading weight could be extended beyond previous limits by positioning a cleaning preparation throughout the interior of the multifilament floss. More particularly, the patents to Hill et al. taught the deposition of a cleaning preparation in spaces between the several strands and between the individual filaments comprising each strand by a process called compression loading. The cleaning preparation activates as the floss splays upon being pulled between the teeth, thereby delivering the cleaning preparation to the oral cavity, especially the surfaces of the teeth.
The classification of plaque as a biofilm is considered a major advance in the development of more effective “self-treatment” oral care products. See the following biofilm references:
Greenstein and Polson, J. Periodontol., May 1998, 69:5:507–520; van Winkelhoff, et al., J. Clin. Periodontol., 1989, 16:128–131; and Wilson, J. Med. Microbiol., 1996, 44:79–87.                Biofilms are defined as “ . . . matrix-enclosed bacterial population adherent to each other and to the surface or intersurfaces. These masses secrete an exopolysaccharide matrix for protection. Considerably higher concentrations of drugs are needed to kill bacteria in biofilms than organisms in aqueous suspensions.”        
Costerton, J. W., Lewandowski, Z., DeBeer, D., Caldwell, D., Korber, D., James, G. Biofilms, the customized microniche. J. Bacterio., 1994, 176:2137–2142.                The unique attributes of biofilms is being recognized as increasingly important in the 1990's. Future studies into the mode of growth of biofilms will allow manipulation of the bacterial distribution.        
Douglass, C. W., Fox, C. H. Cross-sectional studies in periodontal disease: Current status and implications for dental practice. Adv. Dent. Res., 1993, 7:26–31.                The number of adults over 55 who will need periodontal services will increase. The type of services will need to be adjusted to meet the need.        
Greenstein, G. J., Periodontal response to mechanical non-surgical therapy: A review. Periodontol., 1992, 63:118–130.                Mechanical therapy remains effective with caveats of compliance and skill of therapists.        
Marsh, P. D., Bradshaw, D. J. Physiological approaches to the control of oral biofilms. Adv. Dent. Res., 1997, 11:176–185.                Most laboratory and clinical findings support the concept of physiological control. Further studies will reveal details of biofilm diversity.        
Page, R. C., Offenbacher, S., Shroeder, H., Seymour, G. J., Kornman, K. S. Advances in the pathogenesis of periodontitis: Summary of developments, clinical implications and future directions. Periodont. 2000, 1997, 14:216–248.                Genetic susceptibility to three oral anaerobic bacteria play an important part in the progression of periodontitis. Acquired and environmental risk factors exacerbate the problem. Mechanical disruption will remain an effective and essential part of periodontal therapy.        
Papapanou, P. N., Engebretson, S. P., Lamster, I. B. Current and future approaches for diagnosis of periodontal disease. NY State Dent. J., 1999, 32–39.                New techniques are available such as a novel pocket depth measurement device, microscopic techniques, immunoassay, DNA probes, BANA hydrolysis tests. These more clearly define the nature of periodontitis.        